* consistent efficient performance
* substantially longer service life with minimal disposal requirements
* universal availability
* independent of toxic and limited resources
* small vehicle to generating station capacity
* well developed technology
* low weight and low capital cost
The Refrigerated Compression Gas Turbine (RCGT) described by a Cryogenic Brayton Cycle offers least refrigerant consumption of the cryogenic engines, which are at various stages of development. The gas turbine has several advantages including ability to burn most fuels or run on recovered heat. Reliability is high while maintenance, weight and emissions are low. The gas turbine is potentially a universal prime mover, however it is inefficient in small engines, especially in variable speed vehicle application. Low compression work of the RCGT extends high efficiency to small units and the gas turbine is readily converted to injection of liquid air or nitrogen into an external and independently driven compressor.
It is useful to re-define some terms associated with renewable energy before proceeding with a discussion involving the dual fluid (fuel and oxidizer/coolant) liquid air engine. The terms "tank-to-wheel” and “well-to-wheel”  used to describe vehicle efficiency including refining, distribution and exploration of fuel, are used herein as “operating” and “total”, respectively, for inclusion of stationary engines, non-fuel heat addition and liquefaction of air.
Performance and Cost
RCGT 1.50 51 19 43 12
Table 2 presents operating efficiency and total efficiency for a solar heated RCGT with a pressure ratio of 3, applicable to distributed generation capacity of 28 kW. Efficiency of a turbine with ambient air compression and battery storage is included for comparison.
Refrigerant economy is improved by utilizing liquefier waste heat in cogeneration, including renewable fuel in station application and space heating in local application.
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